The present invention relates generally to a brake control apparatus or system including: a master cylinder arranged to raise an internal pressure of a wheel cylinder (wheel cylinder pressure) of a vehicle in accordance with operation of an input device of the vehicle; a booster system for raising the wheel cylinder pressure by operating the master cylinder independently of operation of the input device; and a pressure regulator system with a hydraulic pressure source for raising the wheel cylinder pressure independently of operation of the master cylinder. The invention relates particularly to a brake control apparatus which is capable of controlling the wheel cylinder pressure even when the booster system is malfunctioning.
PCT International Publication No. WO98/35867 discloses an automotive brake system which includes a brake booster for assisting operation of a brake pedal by operating a master cylinder, and an ABS (Anti-lock Brake System) provided with a hydraulic pump. When the brake booster is failed, then the brake system controls wheel cylinder pressures by operating the hydraulic pump instead of the brake booster.